Cutting edge apparatus

ABSTRACT

A cutting edge apparatus includes a cylindrical outer pipe to be driven into a ground. The apparatus includes a vibratable vibration cylinder provided within the outer pipe and being movable relative to the outer pipe in an axial direction of the outer pipe. The apparatus includes a cutting edge member substantially identical in outer size with the outer pipe and being integrally mounted to the outer circumference of the end of the vibration cylinder. The apparatus includes a vibrator mounted to the vibration cylinder and configured to vibrate the vibration cylinder. The vibration cylinder has a tapered rear portion so that the rear portion becomes smaller in size as the rear portion extends toward the rear end of the vibration cylinder.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2004-137704 filed on May 6, 2004; theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to a cutting edge apparatus used for tunnelexcavation, and in particular to a cutting edge apparatus whichfacilitates driving of a cutting edge into a ground.

Conventionally, excavation for a tunnel with a relatively small diameter(a diameter up to about several meters) has been performed by workers'hand drilling. In this case, the cutting edge positioned at the distalend of a Hume pipe is propelled by a propelling apparatus such as ahydraulic jack to be driven into the ground. Workers drill the groundand remove soil produced from the cutting face of a tunnel to excavate atunnel.

In the tunnel excavation, the cutting face may collapse. The collapsecauses a large amount of soil to enter the cutting edge, thereby riskingworkers' safety and rendering working in front of the cutting edgedifficult.

A cutting edge apparatus that ensures safe tunnel excavation even whenthere is a risk, such as collapse of a cutting face, has been proposed(see Japanese Patent Application Laid-open No. 2002-242584, forexample).

In the cutting edge apparatus, the cylindrical outer pipe has a cuttingedge to be driven into the ground at the distal end thereof. The outerpipe has a tapered conical main unit vibrated by a vibration motortherein. When the cutting face of the tunnel collapses, deposition ofsoil in the conical main unit allows for safe tunnel excavation, whichis considerably effective for safety ensuring.

In the above structure, vibrations of the conical main unit caused bythe vibration motor reduce friction between the conical main unit andfallen soil, thus easily correcting propelling and directionality of thecutting edge apparatus.

Furthermore, the cutting edge and the conical main unit are providedseparately from each other for easy replacement of a worn cutting edge.

In the above structure, however, driving of the cutting edge into a firmground requires a large force, and the structure should be furtherimproved.

SUMMARY OF THE INVENTION

The aspect of the invention provides a cutting edge apparatus. Theapparatus includes a cylindrical outer pipe to be driven into a ground.The apparatus includes a vibratable vibration cylinder provided withinthe outer pipe and being movable relative to the outer pipe in an axialdirection of the outer pipe. The apparatus includes a cutting edgemember substantially identical in outer size with the outer pipe andbeing integrally mounted to the outer circumference of the end of thevibration cylinder. The apparatus includes a vibrator mounted to thevibration cylinder and configured to vibrate the vibration cylinder. Thevibration cylinder has a tapered rear portion so that the rear portionbecomes smaller in size as the rear portion extends toward the rear endof the vibration cylinder.

The cutting edge member may have a distal end coated with a hardmaterial.

The cutting edge apparatus may include a lubrication supplier configuredto supply a lubricant to the outer pipe or the outer circumferentialsurface of a following pipe provided at the back of the outer pipe.

The cutting edge member may be fixed to the outer circumference of theend of the vibration cylinder.

The invention allows for excavation of a tunnel, vibrating the cuttingedge member. This way facilitates driving of the cutting edge memberinto a ground. This way allows the tapered portion of the cutting edgemember to receive the fallen soil during falling of the cutting face ofthe tunnel, thus ensuring safety.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a sectional view of a cutting edge apparatus according to anembodiment of the invention;

FIG. 2 is a plan sectional view of the cutting edge apparatus shown inFIG. 1;

FIG. 3 is a right side view of the cutting edge apparatus and thefollowing pipe as viewed from arrows III-A and III-B in FIG. 1, wherethe left half as indicated by III-A illustrates the cutting edgeapparatus, and the right half as indicated by III-B illustrates thefollowing pipe; and

FIG. 4 is a schematic view illustrating excavation facilities using thecutting edge apparatus shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1, a cutting edge apparatus 1 according to anembodiment of the invention includes a cylindrical outer pipe 5 drivenin a ground 3 by a propelling apparatus such as hydraulic jackingcylinders 127 a and 127 b (see FIG. 4). The cutting edge apparatus 1includes a vibration cylinder 7 mounted inside the outer pipe 5 to bemovable in an axial direction of the outer pipe 5 and be capable ofvibrating.

In more detail, the vibration cylinder 7 includes an inner pipe 11supported within the outer cylinder 5 via an annular sealing member 9 tobe movable in an axial direction and be capable of vibrating. The frontend of the inner pipe 11 is integrally welded to a stopper ring 13. Thestopper ring 13 abuts against a stopper 15 provided on the inner face ofthe outer pipe 5 to restrict the vibration cylinder 7 to movement in aforward direction (the left direction in FIG. 1).

The front end of the stopper ring 13 is integrally fixed, by welding orthe like, to the rear end of a taper ring 17 whose diameter graduallyincreases toward the front end thereof. The outer periphery of the frontend of the taper ring 17 is integrally welded to a guide ring 19 with anouter diameter slightly smaller than the inner diameter of the outerpipe 5. The guide ring 19 has an outer peripheral face projecting fromthe front end face (the left end face in FIG. 1) of the outer pipe 5.The outer peripheral face is integrally welded to a ring-like cuttingedge member 21 with an outer diameter approximately equal to that of theouter pipe 5. The rear end face (a right end face in FIG. 1) of thecutting edge member 21 serves as an abutting face that is abutablerelatively against the front end face of the outer pipe 5. The rear endof the cutting edge member 21 and the front end of the outer pipe 5 havean allowance 20 therebetween.

That is, when the propelling apparatus pushes against the outer pipe 5in a forward direction, the front end face of the outer pipe 5 and therear end face of the cutting edge member 21 abut against each other todrive the cutting edge member 21 into the ground 3. The step portionbetween the taper ring 17 and the guide ring 19 and the step portionbetween the guide ring 19 and the cutting edge member 21 are welded in ataper shape. The taper shape eliminates the step portion to allow forsmooth driving of the cutting edge member 21 into the ground. Theannular front end face of the cutting edge member 21 is coated with anappropriate hard material 23 having excellent wear resistance and impactresistance, such as alloy tool steel, high-speed steel, or hard metal byspraying.

The structure allows tunnel excavation even if the ground 3 is firm, andachieves a long life of the cutting edge member 21.

The rear portion of the inner pipe 11 gradually decreases in diametertoward the rear end. The rear portion of the inner pipe 11 is integrallywelded to a taper body 25. The taper body 25 with a tapered cylindricalshape has a circular opening portion 25 a at the rear end portion, andthe area of the opening portion 25 a is about a fourth (¼) of a circulararea surrounded by the cutting edge member 21. The opening portion 25 awith a small diameter of the taper body 25 is attached with a lid 29 tobe openable and closable using a hinge 27 (see FIG. 2). The openingportion 25 a has a lock handle 31 (see FIG. 4) that locks the lid 29 toa closed state thereof.

The taper body 25 is vibratably supported to the outer pipe 5 by elasticmembers 33 such as rubbers provided at a plurality of portions on theinner peripheral face on the outer cylinder 5. The taper body 25 ismounted with vibrators 35 such as vibration motors, which appliesvibrations to the taper body 25. The outer peripheral face of the taperbody 25 has an abutting member 39 fixed thereon. The rear end portion ofthe abutting member 39 is abutable against the front face of a ring-likebracket 37 provided on the inner peripheral face of the outer pipe 5.

A clearance 38 between the bracket 37 and the abutting member 39 is setto be approximately equal to a clearance 20 between the front end faceof the outer pipe 5 and the rear end face of the cutting edge member 21.When the outer pipe 5 and the cutting edge member 21 abut against eachother to push forward (propel) the cutting edge member 21, the bracket37 abuts against the abutting member 39 to push forward the taper body25. That is, the cutting edge member 21 and the taper body 25 areintegrally pushed forward in synchronization with each other. Thestructure disperses portions being pushed, while the cutting edge member21 is being pushed forward by the outer pipe 5, thereby suppressingstress.

The rear end of the outer pipe 5 has a following pipe 41 for propelling(pushing forward) the outer pipe 5. In detail, the outer diameter of thefollowing pipe 41 is slightly smaller than an outer diameter of theouter pipe 5. The front end portion of the following pipe 41 abutsagainst an annular abutting member 43 provided on the inner peripheralface of the outer pipe 5 near the rear end thereof. The outer peripheralface of the distal end portion of the following pipe 41 and the innerperipheral face of the outer pipe 5 have an annular sealing member 45made from rubber mounted therebetween.

The inner peripheral face of the following pipe 41 near the rear end hasan annular distal end face abutting member 49 to be pushed forward bythe distal end face of the Hume pipe 47. The annular chamber 51 isformed at the front side (the left side in FIG. 1) of the distal endface abutting member 49. The chamber 51 reserves lubricant. The innerperipheral face of the chamber 51 is formed with a plurality ofsupplying ports 53 for supplying lubricant. The inner peripheral face 51has an inspection port 59 that is closed by a lid member 57 attachableor detachable by a fixing tool 55 such as a plurality of bolts.

The outer peripheral face of the following pipe 41 has an annularopening member 63 corresponding to the chamber 51. The opening member 63is provided with opening portions 61 (see FIG. 2) opened so as to beenlarged rearward and formed along a circumferential direction thereofat proper intervals. The outer peripheral face of the opening member 63is covered with an annular cover 65. The opening portions 61 havecommunication holes 67 opened to the following pipe 41 and communicatingwith the chamber 51.

When lubricant such as oil is properly supplied from the supplying ports53 into the chamber 51, lubricant in the chamber 51 is supplied to theopening portions 61 so that lubricant is supplied on the outerperipheral face of the Hume pipe 47 through the opening portions 61.Thereby, while the Hume pipe 47 is being pushed forward by a propellingapparatus such as a hydraulic jack, friction between the Hume pipe 47and the ground 3 is made small, thereby facilitating pushing of the Humepipe 47. The condition of the lubricant in the chamber 51 is confirmedthrough the inspection port 59. When, for example, lubricant has beenconsolidated, detachment of the lid member 57 permits the lubricant tobe easily taken out of the chamber 51.

In the structure, when the propelling apparatus pushes forward againstthe Hume pipe 47, the Hume pipe 47 pushes against the following pipe 41and the following pipe 41 pushes against the outer pipe 5. When theouter pipe 5 is pushed forward, the distal end face (the front end face)of the outer pipe 5 abuts against the cutting edge member 21 to bepushed forward, thus driving the cutting edge member 21 into the ground3.

During the driving-into, when the vibrators 35 are driven to vibrate thetaper body 25, integral provision of the taper body 25 and the cuttingedge member 21 allows integral vibrations thereof. Thereby, the cuttingedge member 21 is driven while being vibrated to the ground 3. Even ifthe ground 3 is firm, effective driving is allowed to improveefficiency.

When the cutting edge member 21 is driven into the ground 3, the lid 29is held in a closed state thereof, considering collapse of a cuttingface of the ground 3. After the cutting edge member 21 is driven intothe ground 3, the lid 29 is opened. The cutting edge member 21 thenexcavates the cutting face of the ground 3 in a surrounded state, thusexcavating a tunnel.

After soil produced by excavation is ejected from the taper body 25, thepropelling apparatus drives the cutting edge member 21 into the ground 3again. Repetition of this work continuously performs tunnel excavation.

As understood from the descriptions, the taper body 25 and the cuttingedge member 21 integrally provided vibrate integrally. This vibrationfacilitates driving of the cutting edge member 21 into the firm ground 3as compared with the conventional system. When a large amount of fallensoil is present inside the taper body 25, the vibration reduces frictionbetween fallen soil and the taper body 25, thus facilitating directionalcorrection of the cutting edge member 21.

The coating of the hard material 23 on the distal end portion of thecutting edge member 21 enhances wear resistance and impact resistance,thereby, allowing for the long life in the cutting edge member 21.

Further, the following pipe 41 has the lubricant supplying ports whichsupply lubricant to the outer peripheral face of the Hume pipe 47, thusreducing friction occurring during pushing of the Hume pipe 47 forward.

The structure is applied to the outer pipe 5, and the lubricantsupplying ports may be provided in the outer pipe 5.

With reference to FIG. 4, excavation facilities 100 to which the cuttingedge apparatus 1 is applied will be described.

The excavation facilities 100 include a cutting edge apparatus 1 whichexcavates the ground 3. The excavation facilities 100 include a jackingpipe 101 serving as a Hume pipe 47 communicating with the cutting edgeapparatus 1. The end of the jacking pipe 101 projects above the pitfloor 121 within a pit 113. The excavation facilities 100 include abattery feeder 103 feeding power to the vibrators 35. The excavationfacilities 100 include a compressed air-mixer 105 and a flexible pipe107 connected to the compressed air-mixer 105 in the jacking pipe 101.The excavation facilities 100 include a vacuum pump 109 connected to theflexible pipe 107. Soil produced by excavation is conveyed by a truck111.

The excavation facilities 100 include an adapter 123 mounted at the endof the jacking pipe 101 in the pit 113. The excavation facilities 100include a reaction wall 125 provided on the side wall of the pit 113.The excavation facilities 100 include jacking cylinders 127 a and 127 bserving as a propelling apparatus arranged between the reaction wall 125and the adapter 123.

The excavation facilities 100 include a generator 131 and a power pack133 for supplying power to the battery feeder 103. The excavationfacilities 100 include, outside the pit 113, a lubrication pump 135serving as a lubricant supplying section, which supplies lubricant tothe jacking pipe 101. A hydraulic crane 137 which conveys, for example,jacking pipes 101, is put on standby outside the pit 113.

A method of operating the excavation facilities 100 will be described.

When the jacking cylinders 127 a and 127 b push against the jacking pipe101 forward, the jacking pipe 101 pushes against the outer pipe 5 of thecutting edge apparatus 1 to drive the cutting edge member 21 into theground 3. During the driving-into, the lubrication pump 135 supplieslubricant to the outer face of the jacking pipe 101.

The generator 131 supplies power to the vibrators 35 via the batterypack 133 and the battery feeder 103. The vibrators 35 vibrate thecutting edge member 21 as well as the vibration cylinder 7. The cuttingedge member 21 excavates a tunnel in the ground 3.

Soil produced by excavation is sucked up on a ground via the flexiblepipe 107 by the vacuum pump 109, and it is loaded on the truck 111.

When the cutting edge apparatus 1 goes into the ground 3 at a fixeddistance, a new jacking pipe is hung down in the pit 113 by thehydraulic crane 137. The new jacking pipe is set to the end of thejacking pipe 101 in use.

Although the invention has been described above by reference to certainembodiments of the invention, the invention is not limited to theembodiments described above. Modifications and variations of theembodiments described above will occur to those skilled in the art, inlight of the above teachings. The scope of the invention is defined withreference to the following claims.

1. A cutting edge apparatus comprising: a cylindrical outer pipe to bedriven into a ground; a vibratable vibration cylinder provided withinthe outer pipe and being movable relative to the outer pipe in an axialdirection of the outer pipe; a cutting edge member substantiallyidentical in outer size with the outer pipe and being integrally mountedto the outer circumference of the end of the vibration cylinder; and avibrator mounted to the vibration cylinder and configured to vibrate thevibration cylinder, wherein the vibration cylinder has a tapered rearportion so that the rear portion becomes smaller in size as the rearportion extends toward the rear end of the vibration cylinder.
 2. Thecutting edge apparatus according to claim 1, wherein the cutting edgemember has a distal end coated with a hard material.
 3. The cutting edgeapparatus according to claim 1, further comprising: a lubricationsupplier configured to supply a lubricant to the outer pipe or the outercircumferential surface of a following pipe provided at the back of theouter pipe.
 4. The cutting edge apparatus according to claim 1, whereinthe cutting edge member is fixed to the outer circumference of the endof the vibration cylinder.